This invention relates to olefin polymerization and more particularly relates to deactivating catalyst residues and to removal of the volatiles and oligomers from polyolefins, especially polypropylene.
In production of high molecular weight, solid, polyolefins, typically low molecular weight volatile species such as oligomers also are produced. If high levels of oligomeric materials remain in the polymer, problems typically are encountered when the polymer is used in commercial molding machines in that excessive smoke, referred to as "die smoke", is produced.
Also in the manufacture of polyolefins, especially propylene polymers, catalyst residue remains in the polymer after polymerization. This residue typically must be deactivated in order to avoid polymer corrosivity.
The invention described herein presents a method which effectively deactivates polymerization catalyst residue, while minimizing die smoke in subsequent polymer processing.